Researchers develop stroke risk system

NAGOYA – Japanese researchers have developed a point-based system that can predict the risk of a stroke over 10 years.

Blood pressure levels, smoking and other risk factors are taken into account in the prediction model, the researchers, including Fujita Health University professor Hiroshi Yatsuya in Toyoake, Aichi Prefecture, said Tuesday.

In cooperation with the National Cancer Center, Yatsuya created the model based on the results of research on the health of 16,000 adults surveyed across the country between 1993 and 2007.

The model awards a subject points in accordance with the risk values set for six factors: age, sex, current smoking habit, presence or absence of diabetes, body mass index and blood pressure. The points are then used to calculate the 10-year stroke risk and the age of the blood vessels of a subject.

For example, a 50-year-old male smoker gets 6 points for his age, another 6 for his sex and a further 4 for his smoking habit. If his body mass index is 26, slightly over the standard, he gets an additional 2 points. He gets zero points if he does not have diabetes, but 6 if his systolic blood pressure without antihypertensive medication is 135 mmHg and the diastolic pressure is 85 mmHg.

For a man with 24 points in total, the model indicates his blood vessels’ age as that of 64 year old — 14 years older than his actual age — and his 10-year stroke risk is calculated at between 3 and 4 percent.

High blood pressure is seen as the biggest risk factor, apart from age. For men, the second is diabetes, followed by smoking and obesity. Smoking ranks second for women, followed by diabetes and obesity.